Power supply vendors offer Time of Use (TOU) tariff plans where the electricity per unit price will vary depending on the time popularly known as peak, off peak and shoulder time slabs. Customers with advanced meters and time of use tariffs pay different amounts for their electricity over these three different time periods. Power prices are cheaper in the off peak period and the peak time prices vary from 5 to 10 times the off peak period prices depending on countries. The shoulder period which could constitute up to 51% of the time depending on the countries and the price during this time is varied in between the peak period and off peak period tariff.
Management of tariff schedules involves using information on tariff changes supplied directly or indirectly by the electric power distributor to control and monitor the switching on of certain appliances under the most favorable economic conditions to the user. The usual household energy management system can mainly perform the tasks such as switching off the appliances if no user exists and the standby power cutoff by which the standby power otherwise consumed by household appliances are cutoff.
The tariff schedule management is currently performed using a relay that is controlled by means of signals directly transmitted by the electric power distributor or locally controlled by a clock and situated close to the electricity meter which makes it possible to control the operation of a load depending on the availability of the so-called off-peak tariff. Since the use of “off-peak” tariff is advantageous for all appliances that consume large amounts of power such as washing machines, tumble driers, dishwashers, heating appliances etc., the current solution required to be improved efficiently to manage the power in order to reduce the electricity bill.
However, the energy saving by control of household electric appliances is not so great within the consumer entity employing the conventional household energy management system. To realize increased energy saving, it is necessary to actively collaborate in reducing energy consumption in peak hours and utilize off peak hours more efficiently. User has to pay heavy electricity price if the consumption during the peak hour is not controllable. The load during peak hour can be controlled either by changing the source of power consumption and/or by shutting down the non critical load, but doing it manual is risky, prone to errors and inconvenient.
Moreover, user has to remember the time slabs and has to manually program the usage of the power source, to manually shut the non critical loads during peak time, which is not convenient to operate. Further, lack of communication between inverter systems and the user, and communication failure between the grid and the user also become a big problem in regulating the power consumption. Sometimes the user may be away from the place where inverter is installed, resulting uncontrolled electricity distribution. User is always surprised when the electricity bills arrives due to uncontrolled electricity usage during peak time. Thus the conventional approach fails to efficiently regulate the electricity consumption, since the tariff changes are linked more directly to the supply and demand for power.
Accordingly, it is necessary to provide an improved system for managing the energy consumption which avoids the higher electricity prices and enables running the appliances in a cost effective manner. Therefore it is desirable to provide a system for managing energy consumption, which overcomes the disadvantages of the conventional power consumption control approaches and providing a system which dynamically switches the power supplies during different time slabs so as to minimize the electricity bill. It also helps to utilize the non-conventional source of energy more efficiently.